Make bson-enum_error resilient to PHP 8.6 interface handler order (mongodb#1953)

PHP is calling the interface_gets_implemented handlers in a different order

Author: GromNaN

tests/bson/bson-enum_error-003.phpt

@@ -15,5 +15,5 @@ enum MyEnum implements MongoDB\BSON\Persistable
 ?>
 ===DONE===
 <?php exit(0); ?>
---EXPECTF--
-Fatal error: Enum class MyEnum cannot implement interface MongoDB\BSON\Persistable in %s on line %d
+--EXPECTREGEX--
+Fatal error: Enum class MyEnum cannot implement interface MongoDB\\BSON\\(Persistable|Unserializable) in .+ on line \d+

tests/bson/bson-enum_error-004.phpt

@@ -15,5 +15,5 @@ enum MyBackedEnum: int implements MongoDB\BSON\Persistable
 ?>
 ===DONE===
 <?php exit(0); ?>
---EXPECTF--
-Fatal error: Enum class MyBackedEnum cannot implement interface MongoDB\BSON\Persistable in %s on line %d
+--EXPECTREGEX--
+Fatal error: Enum class MyBackedEnum cannot implement interface MongoDB\\BSON\\(Persistable|Unserializable) in .+ on line \d+